Aggressive Aero Riding Position

I have a Cervelo dual and I have recently updated my aero riding position. The Dual has a dual position seat post that allows you to have a 75 degree or 78 degree seatpost angle. Also, it comes stock with about 4-5 centimeters of spacers above the head tube.

I recently update my position by removing the spacers and moving the seat to the forward position. I used Dan Empfield's tri bike fit article to evaluate my position and adjust it to the new position. See his article http://www.slowtwitch.com/mainheadings/techctr/bikefit.html

I connected my camcorder up to my computer, put my bike on my trainer and captured video frames that I could compare to Dan's diagrams. I overlayed lines that let me measure my hip angle, shoulder angle, and knee extension angle. I adjusted these until I had the most aggressive aero position (78 degree seat post angle, 150 degree knee extension, lowest handle bar setting on the dual) and still keep the proper right angles for my hip and shoulder joints.

I have ridden several hours in this new posture and I am reasonably comfortable with it even though the is a little more pressure on the forward part of my crotch. I have only done a short ride on the road, so I don't know what the performance impact will be yet.

Does anyone have experience with the more aggressive riding postures? How much drag/time/speed is the more aggressive posture worth? And does anyone have any comments on Dan's fitting methodology? Please share your experience. Thanks!

Brittain